There are no known causes of Bipolar Disorders, but there are many well researched theories. These theories include; neurons, heredity, chromosomes and brain activity.
Neurons (brain cells)
The brain needs specific chemicals in certain amounts to function “normally.” It has been found that in people with Bipolar Disorder these chemicals are imbalanced. The cells of the brain, which are called neurons, communicate with each other and cause chemicals to be release, which effect the way the body functions. Chemicals such as norepinephrine, dopamine, and serotonin either excite or calm the neurons and in turn the body (which is a series of neurons). In people with Bipolar disorder, these chemicals are often out of balance. If Seratonin and norepinephrine and decreased the person may be depressed. If the chemical dopamine is increased, schizophrenia or other mental illnesses may occur. In people with bipolar disorders, may be caused by these extreme changes in chemicals.
It has been observed that bipolar disorders run in families. Family, twin and adoption studies show that there is a strong possibility that there is a genetic component to bipolar disorders.
Experts have noticed a link between a person’s thyroid hormone levels and bipolar disorder.
Recently, chromosome 22 has been related to a variety of mental illnesses, including bipolar disorder. This finding may lead to a better understanding of bipolar disorder and lead to better treatments.
Brain imaging studies suggest that there are structural abnormalities in different parts of the brain of a person with a bipolar disorder.
From left: view of a nomal brain; patient with bipolar disorder has enlarged ventricles (fills with fluid to cushion the brain); bright white spots of hyperintensity associated with bipolar illness.
It has also been found that brain activity can vary in people with a bipolar disorder.